Name: histology basics and cell death detection in honeybee tissue
Uploaded: 2022-07-07T14:00:00
Description: Watch this Scientific Journal Video about Histology Basics and Cell Death Detection in Honeybee Tissue at JoVE.com

I gratefully acknowledge the support of the Slovenian Research Agency, grant no. P4-133.

1. Basic histology for honeybee research
<ol>
	<li>Dissection of honeybee tissue 
	NOTE: For the dissection of worker bees, use a dissecting microscope with an LED light source. The most useful magnification is ~20x.
	<ol>
		<li>Manipulation and dissection
		<ol>
			<li>Carefully take a worker bee with forceps and put it on ice (or into the freezer at -20 &#176;C) for 2 min to immobilize it22. Pin the bee on the Petri dish diagonally through the uppermost back portion of th...

<ol>
	<li>Ruttner, F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Naturgeschichte der Honigbienen. , (1992).</li><li>Jordan, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Kleine+Bienenkunde.">Kleine Bienenkunde.</a> &#214;sterreichischer Agrarverlag Wien M&#252;nchen. , 41-45 (1964).</li><li>Snodgrass, R. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+Anatomy+of+the+Honey+Bee.">The Anatomy of the Honey Bee.</a> The Hive and the Honey Bee. , 111-113 (1975).</li><li>Snodgrass, R. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> The Anatomy of the Honey Bee. , (2004).</li><li>Hrassnigg, N., Crailsheim, K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Adaptation+of+hypopharyngeal+gland+development+to+the+brood+status+of+honeybee+(Apis+mellifera+L.)+colonies.">Adaptation of hypopharyngeal gland development to the brood status of honeybee (Apis mellifera L.) colonies.</a> Journal of Insect Physiology. 44 (10), 929-939 (1998).</li><li>Smodi&#353; &#352;kerl, M. I., Gregorc, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Characteristics+of+hypopharyngeal+glands+in+honeybees+(Apis+mellifera+carnica)+from+a+nurse+colony.">Characteristics of hypopharyngeal glands in honeybees (Apis mellifera carnica) from a nurse colony.</a> Slovenian Veterinary Research. 52 (2), 67-74 (2015).</li><li>Kubo, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Change+in+the+expression+of+hypopharyngeal-gland+proteins+of+the+worker+honeybees+(Apis+mellifera+L.)+with+age+and/or+role.">Change in the expression of hypopharyngeal-gland proteins of the worker honeybees (Apis mellifera L.) with age and/or role.</a> Journal of Biochemistry. 119 (2), 291-295 (1996).</li><li>Sammataro, D., Yoder, J. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Honey bee colony health: Challenges and sustainable solutions. , 302 (2012).</li><li>Crailsheim, K., Stolberg, E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Influence+of+diet,+age+and+colony+condition+upon+intestinal+proteolytic+activity+and+size+of+the+hypopharyngeal+glands+in+the+honeybee+(Apis+mellifera+L.).">Influence of diet, age and colony condition upon intestinal proteolytic activity and size of the hypopharyngeal glands in the honeybee (Apis mellifera L.).</a> Journal of Insect Physiology. 35 (8), 595-602 (1998).</li><li>Smodi&#353; &#352;kerl, M. I., Gregorc, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Heat+shock+proteins+and+cell+death+in+situ+localisation+in+hypopharyngeal+glands+of+honeybee+(Apis+mellifera+carnica)+workers+after+imidacloprid+or+coumaphos+treatment.">Heat shock proteins and cell death in situ localisation in hypopharyngeal glands of honeybee (Apis mellifera carnica) workers after imidacloprid or coumaphos treatment.</a> Apidologie. 41 (1), 73-86 (2010).</li><li>Gregorc, A., Bowen, I. D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+histochemical+characterisation+of+cell+death+in+honeybee+larvae+midgut+after+treatment+with+Paenibacillus+larvae,+Amitraz+and+Oxytetracycline.">The histochemical characterisation of cell death in honeybee larvae midgut after treatment with Paenibacillus larvae, Amitraz and Oxytetracycline.</a> Cell Biology International. 24 (5), 319-324 (2000).</li><li>Higes, M., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Apoptosis+in+the+pathogenesis+of+Nosema+ceranae+(Microsporidia:+Nosematidae)+in+honey+bees+(Apis+mellifera).">Apoptosis in the pathogenesis of Nosema ceranae (Microsporidia: Nosematidae) in honey bees (Apis mellifera).</a> Environmental Microbiology Reports. 5 (4), 530-536 (2013).</li><li>Kurze, C., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Infection+dynamics+of+Nosema+ceranae+in+honey+bee+midgut+and+host+cell+apoptosis.">Infection dynamics of Nosema ceranae in honey bee midgut and host cell apoptosis.</a> Journal of Invertebrate Pathology. 154, 1-4 (2018).</li><li>Johnson, R. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Honey+bee+toxicology.">Honey bee toxicology.</a> Annual Review of Entomology. 60 (1), 415-434 (2005).</li><li>Gashout, H. A., Guzman-Novoa, E., Goodwin, P. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Synthetic+and+natural+acaricides+impair+hygienic+and+foraging+behaviors+of+honey+bees.">Synthetic and natural acaricides impair hygienic and foraging behaviors of honey bees.</a> Apidologie. 51 (6), 1155-1165 (2020).</li><li>McMenamin, A. J., Genersch, E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Honey+bee+colony+losses+and+associated+viruses.">Honey bee colony losses and associated viruses.</a> Current Opinion in Insect Science. 8, 121-129 (2015).</li><li>Ramsey, S. D., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Varroa+destructor+feeds+primarily+on+honey+bee+fat+body+tissue+and+not+hemolymph.">Varroa destructor feeds primarily on honey bee fat body tissue and not hemolymph.</a> Proceedings of the National Academy of Sciences USA. 116 (5), 1792-1801 (2019).</li><li>Requier, F., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Honey+bee+diet+in+intensive+farmland+habitats+reveals+an+unexpectedly+high+flower+richness+and+a+major+role+of+weeds.">Honey bee diet in intensive farmland habitats reveals an unexpectedly high flower richness and a major role of weeds.</a> Ecological Applications. 25 (4), 881-890 (2015).</li><li>Santos, C., Serr&#227;o, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Histology+of+the+ileum+in+bees+(Hymenoptera,+Apoidea).">Histology of the ileum in bees (Hymenoptera, Apoidea).</a> Brazilian Journal of Morphological Sciences. 23 (3), 405-413 (2006).</li><li>Suwannapong, G., Saichon, C., Benbow, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Histochemical+comparison+of+the+hypopharyngeal+gland+in+Apis+cerana+Fabricius,+1793+workers+and+Apis+mellifera+Linnaeus,+1758+workers.">Histochemical comparison of the hypopharyngeal gland in Apis cerana Fabricius, 1793 workers and Apis mellifera Linnaeus, 1758 workers.</a> Psyche: A Journal of Entomology. , (2010).</li><li>Ceylan, A., Sevin, S., &#214;zgen&#231;, &. #. 2. 1. 4. ;. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Histomorphological+and+histochemical+structure+of+the+midgut+and+hindgut+of+the+Caucasian+honey+bee+(Apis+mellifera+caucasia).">Histomorphological and histochemical structure of the midgut and hindgut of the Caucasian honey bee (Apis mellifera caucasia).</a> Turkish Journal of Veterinary and Animal Sciences. 43 (6), 747-753 (2019).</li><li>Human, H., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Miscellaneous+standard+methods+for+Apis+mellifera+research.">Miscellaneous standard methods for Apis mellifera research.</a> Journal of Apicultural Research. 52 (4), 1-53 (2013).</li><li>Gregorc, A., Smodi&#353; &#352;kerl, M. I. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Toxicological+and+immunohistochemical+testing+of+honeybees+after+oxalic+and+rotenone+treatments.">Toxicological and immunohistochemical testing of honeybees after oxalic and rotenone treatments.</a> Apidologie. 38 (3), 296-305 (2007).</li><li>Carreck, N. L., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Standard+methods+for+Apis+mellifera+anatomy+and+dissection.">Standard methods for Apis mellifera anatomy and dissection.</a> Journal of Apicultural Research. 52 (4), 1-40 (2013).</li><li>Bowen, I. D., Bowen, S. M., Jones, A. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Mitosis and apoptosis: Matters of Life and Death. , (1998).</li><li>Eisenberg-Lerner, A., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Life+and+death+partners:+apoptosis,+autophagy+and+the+cross-talk+between+them.">Life and death partners: apoptosis, autophagy and the cross-talk between them.</a> Cell Death and Differentiation. 16 (7), 966-975 (2009).</li><li>Bowen, I. D., Mullarkey, K., Morgan, S. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Programmed+cell+death+in+the+salivary+gland+of+the+blow+fly+Calliphora+vomitoria.">Programmed cell death in the salivary gland of the blow fly Calliphora vomitoria.</a> Microscopy Research Techniques. 34, 202-207 (1996).</li><li>D'Arcy, M. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Cell+death:+a+review+of+the+major+forms+of+apoptosis,+necrosis+and+autophagy.">Cell death: a review of the major forms of apoptosis, necrosis and autophagy.</a> Cell Biology International. 43 (6), 582-592 (2019).</li><li>Matylevitch, N. P., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Apoptosis+and+accidental+cell+death+in+cultured+human+keratinocytes+after+thermal+injury.">Apoptosis and accidental cell death in cultured human keratinocytes after thermal injury.</a> American Journal of Pathology. 153 (2), 567-577 (1998).</li><li>Perry, S. W., Epstein, L. G., Gelbard, H. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Simultaneous+in+situ+detection+of+apoptosis+and+necrosis+in+monolayer+cultures+by+TUNEL+and+trypan+blue+staining.">Simultaneous in situ detection of apoptosis and necrosis in monolayer cultures by TUNEL and trypan blue staining.</a> BioTechniques. 22 (6), 1102-1106 (1997).</li><li>Cuello-Carrion, F. D., Ciocca, D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Improved+detection+of+apoptotic+cells+using+a+modified+in+situ+TUNEL+technique.">Improved detection of apoptotic cells using a modified in situ TUNEL technique.</a> Journal of Histochemistry and Cytochemistry. 47 (6), 837-839 (1999).</li><li>Gregorc, A., Bowen, I. D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Programmed+cell+death+in+the+honeybee+(Apis+mellifera+L.)+larvae+midgut.">Programmed cell death in the honeybee (Apis mellifera L.) larvae midgut.</a> Cell Biology International. 21 (3), 151-158 (1997).</li><li>Gregorc, A., Poga&#269;nik, A., Bowen, I. D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Cell+death+in+honey+bee+(Apis+mellifera)+larvae+treated+with+oxalic+or+formic+acid.">Cell death in honey bee (Apis mellifera) larvae treated with oxalic or formic acid.</a> Apidologie. 35 (5), 453-460 (2004).</li></ol>

In living organisms, cell death is defined as apoptosis or necrosis25&#160;and can be accompanied by autophagy26. The difference between apoptotic and necrotic cells is that apoptosis is a form of programmed cell death and appears in normal cells, whereas necrosis occurs due to lethal conditions (e.g., accident, disease)27,28. Apoptosis can be detected using assay kits based on the TUNEL technique (detection ofDNA f...

Honeybees (Apis mellifera L.) are, among other wild pollinators, the most important pollinators of agricultural plants. Over thousands of years, the changing environment has influenced bees to adapt their morphology, physiology, behavior, and tolerance to several pathogens and parasites. Therefore, honeybees have developed a highly diverse range of species and subspecies around the globe1. These results are consistent with previous findings, that there is genetic variation in the honeybee&#39;s digestive tract structure, but also suggest that alterations of the midgut are due to environmental factors2,3.
The digestive tract of the honeybee has three main parts: foregut, midgut (ventriculus), and hindgut4. The ventriculus is an essential organ for the digestion of pollen and nectar/honey; in the hindgut, osmotic control takes place through absorption of water and ions2. The hypopharyngeal glands (HPGs) of honeybee workers are located in the head and synthesize and secrete royal jelly components to feed the brood, the queen, and members of the colony. Their size changes with age and tasks and depends on proper nutrition (quality pollen). Nurse workers aged 6 to 18 days perform brood rearing, and the size of HPGs increases5,6. In forager bees, the HPGs degenerate and only secrete enzymes that are important to convert the complex sugars into simple ones (&#945;-glucosidases, leucine arylamidase, invertase) in honey7.
Honeybees are exposed to several biotic and abiotic stressors8, and the digestive tract can be affected by several negative stimulants. The first barrier that protects the organism from pathogens is the peritrophic membrane in the midgut, which consists of intestinal mucosa to protect against pathogens4. The development and function of HPGs depend on diet, age, and colony condition9, and are affected by insecticides, acaricides10, and pathogens11,12,13. Acaricide residues in the hive due to varroa control treatment and pesticides from the environment affect forager bees and nurse bees14,15. The greatest threat to honeybee colonies is the mite Varroa destructor, both as a vector of viruses contributing to colony losses16&#160;and as a consumer of the host&#39;s fat body (an important vital organ in honeybees), which consequently affects the individual&#39;s body and colony functions17.
However, intensive farmland habitats can provide a short-term food supply for honeybees. Therefore, agri-environmental schemes should enhance the availability of honey flowers in agricultural landscapes18. To assess the morphology of different subspecies6,19,20,21&#160;or sublethal effects of these factors at the cell or tissue levels, especially midgut and HPGs, histological and immunohistochemical methods are practical and sufficiently accurate to be used in histology research in honeybees.

<table border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always">
	<tbody>
		<tr>
			<td>2-Propanol</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>ApopTag Peroxidase kit (ApopTag Peroxidase In Situ Apoptosis Detection)</td>
			<td>Sigma-Aldrich</td>
			<td>S7100</td>
			<td>Assay B, https://www.sigmaaldrich.com/SI/en/product/mm/s7100?gclid=CjwKCA 
			jw7vuUBhBUEiwAEdu2pPanI9SE 
			j81ZTl-nLHEoxXAv7ViKwPA_QRx 
			H7fciMRNcYwR7lbPQbhoCqcQQA 
			vD_BwE; Positive controls included in S7101</td>
		</tr>
		<tr>
			<td>Covers</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>DeadEnd Colorimetric TUNEL system</td>
			<td>Promega</td>
			<td>G7360</td>
			<td>Assay A, https://worldwide.promega.com/products/cell-health-assays/apoptosis-assays/deadend-colorimetric-tunel-system/?catNum=G7360</td>
		</tr>
		<tr>
			<td>Dissecting microscope&#160; (for bee dissection)</td>
			<td>Zeiss</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Distilled water</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Embedding cassette</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>EnVision System alkaline phosphatase kit</td>
			<td>Dako</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Eosin Y Solution</td>
			<td>Sigma-Aldrich</td>
			<td></td>
			<td>alcoholic</td>
		</tr>
		<tr>
			<td>Ethanol</td>
			<td></td>
			<td></td>
			<td>95% (or less pure), 90%, 80%</td>
		</tr>
		<tr>
			<td>Faramount mounting medium, aqueous</td>
			<td>Dako</td>
			<td></td>
			<td>mounting medium</td>
		</tr>
		<tr>
			<td>Flattening table</td>
			<td>Leica</td>
			<td>HI1220</td>
			<td></td>
		</tr>
		<tr>
			<td>Forceps&#160; (for bee dissection)</td>
			<td>Fine science tools</td>
			<td>11294-00</td>
			<td>Standard #4</td>
		</tr>
		<tr>
			<td>Formalin 10%</td>
			<td></td>
			<td></td>
			<td>Formaldehyde</td>
		</tr>
		<tr>
			<td>Hematoxylin</td>
			<td>Sigma-Aldrich</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>HistoChoice Clearing Agent</td>
			<td>Sigma-Aldrich</td>
			<td></td>
			<td>clearing agent</td>
		</tr>
		<tr>
			<td>Hydrogen peroxidase 3%</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Incubator</td>
			<td>BioRad</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Insect pins&#160; (for bee dissection)</td>
			<td>Entosphinx</td>
			<td>44594</td>
			<td>Insect pins stainless steel &#8211; white, size 2</td>
		</tr>
		<tr>
			<td>ISCDDK, AP (In Situ Cell Death Detecteion Kit, Alkaline Phosphatase)</td>
			<td>Roche</td>
			<td>11684809910</td>
			<td>Assay C, https://www.sigmaaldrich.com/deepweb/assets/sigmaaldrich/product/documents/362/737/11684809910b 
			ul.pdf</td>
		</tr>
		<tr>
			<td>KH2PO4</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Lab clock</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Light microscope</td>
			<td>Leica</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Microscope slides</td>
			<td></td>
			<td></td>
			<td>Box with the slides must be preserved in a plastic wrap to prevent dust</td>
		</tr>
		<tr>
			<td>Microtome</td>
			<td>Leica</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Modular tissue embedding station</td>
			<td>Leica</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Na2HPO4</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>NaCl</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Paraformaldehyde 4%</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Paraplast</td>
			<td>Leica</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Pasteur pipettes</td>
			<td></td>
			<td></td>
			<td>1.5 mL; 3 mL</td>
		</tr>
		<tr>
			<td>PBS</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Petri dish&#160; (for bee dissection)</td>
			<td></td>
			<td></td>
			<td>Filled with condensation silicon&#160; (Xantoprene L blue and Universal liquid plus activator)</td>
		</tr>
		<tr>
			<td>Proteinase K</td>
			<td>Merck</td>
			<td>21627</td>
			<td></td>
		</tr>
		<tr>
			<td>Ringers&#39; solution&#160; (for bee dissection)</td>
			<td></td>
			<td></td>
			<td>7.5 g NaCL, 2.38 g Na2HPO4, 2.72 g KH2PO4, 1 L distilled water</td>
		</tr>
		<tr>
			<td>Scissors&#160; (for bee dissection)</td>
			<td>Fine science tools</td>
			<td>1406-09, 14061-09</td>
			<td>Straight and curved, 9 cm</td>
		</tr>
		<tr>
			<td>Universal liquid plus activator&#160; (for bee dissection)</td>
			<td>Kulzer</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Watchmaker&#8217;s forceps (for bee dissection)</td>
			<td>Fine science tools</td>
			<td>91100-12</td>
			<td></td>
		</tr>
		<tr>
			<td>Water bath</td>
			<td>Leica</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Watercolor brush</td>
			<td></td>
			<td></td>
			<td>2x</td>
		</tr>
		<tr>
			<td>Xantoprene L blue&#160; (for bee dissection)</td>
			<td>Kulzer</td>
			<td></td>
			<td></td>
		</tr>
	</tbody>
</table>

histology basics and cell death detection in honeybee tissue

Honeybees (Apis mellifera L.) inside the hive (nurse workers and other hive bees) and outside the hive (foragers) are exposed to climate and weather changes, various pesticides, pathogens, and malnutrition, mainly entering through the mouth and primarily affecting the digestive tracts of adult bees. To understand and prevent the effects of such external and internal stressors on honeybees, one useful research method is the immunohistochemical method. A basic protocol is described to prepare the midgut (ventriculus) and hypopharyngeal glands (HPGs) of adult bees for histological analysis. A detailed methodology is described to assess the level of cell damage and distinguish necrosis from programmed cell death (apoptosis) as a natural process of tissue regeneration. The results of adult honeybee treatment with oxalic acid and pesticides (insecticide and acaricide) and the determination of cell death in the ventriculus and HPGs are presented. The pros and cons of the methodology are also discussed.

Cell death detection in the midgut 
Newly emerged worker bees (Apis mellifera carnica) from the experimental apiary at the Agricultural Institute of Slovenia in Ljubljana were individually treated with 3% oxalic acid (OA)23. OA is frequently used in beekeeping for Varroa destructor control. After the treatment, the worker bees (three from each group) were immobilized on ice. The midgut was dissected and fixed it in 10% formalin. The tissue was then dehydrate...

Watch this Scientific Journal Video about Histology Basics and Cell Death Detection in Honeybee Tissue at JoVE.com

Histology Basics and Cell Death Detection in Honeybee Tissue

Immunohistochemical methods are useful in honeybee research to detect and assess the level of apoptosis and necrosis in the midgut and hypopharyngeal glands of adult bees.

Honeybees (Apis mellifera L.) inside the hive (nurse workers and other hive bees) and outside the hive (foragers) are exposed to climate and weather ...

This protocol is useful in many biological and toxicological studies of honeybees treated with pesticides. It helps to detect the cellular responses of honeybee tissue of acaricides that are used in bee colonies for the treatment against Varroa mites. It is a powerful tool for the detection of sub-little effects on tissue in combination with behavior of bees or other beneficial insects.To begin, carefully take a worker bee with forceps and put it on ice or freezer at minus 20 degrees Celsius for two minutes to immobilize it. Pin the bee on the Petri dish diagonally through the uppermost back portion of the thorax twice from left to right and from right to left. Poor insect saline to cover the body.Place the Petri dish under the stereomicroscope, focus, and adjust. To dissect the midgut, start with the abdomen by inserting one point of the scissors under the tergite A5 in the center of the right side of the bee body. Cut to the tergite A2.Keep the inner blade of the scissors parallel with the side of the body to avoid damaging the internal organs.Turn the scissors left and cut. Gently open the left part of the abdomen and pin it. Using forceps with one hand, gently pull the honeybee stomach upward, and with scissors in the other hand, cut at the very end of the esophagus.Pull the stomach and midgut away from the abdomen and cut at the rectum. Use a pipette with insect saline solution and remove any feces or parts of the tissue. For dissection of hypopharyngeal glands, immobilize a worker bee on ice as described before.Cut the head off and place it on a smaller plate with the antenna facing up. Secure the head with two pins, one through the left compound eye and the second through the right compound eye. Make a cut across the first compound eye on the inner side of the pins, continue to the labrum, and then make another cut on the other side across the second compound eye.Cut off the antennae. Lift off the mask and cut where still attached. Take the forceps and carefully remove the glands together with the brain and part of the compound eyes.For hematoxylin and eosin staining, put the dewaxed, rehydrated sections in hematoxylin for five minutes. Then, carefully place them under running tap water for two minutes. Then, put them into distilled water for one minute and eosin for four minutes.Place the slides 96%ethanol for one minute then 2-propanol for two minutes, and finally into the clearing agent for two minutes. Add mounting medium and a cover glass and let them dry. Observe under a light microscope.Prepare Coplin jars. Prepare proteinase-K. After dewaxing and rehydrating the sections, place the slides in PBS for five minutes.Place the slides flat in the container and add proteinase-K. Wash the slides in distilled water. Quench in endogenous peroxidase at room temperature.Rinse the slides with PBS or water. Place the slides flat in the container and apply equilibration buffer for 10 seconds at room temperature. After wiping around the tissue, add the terminal deoxynucleotidyl transferase enzyme to each section, and incubate in a humidified chamber for one hour at 37 degrees Celsius.Before incubation, put moistened paper towels inside the tray around the slides and cover them with plastic wrap. After incubation, put the specimens on the rack and leave them in stop-wash buffer. After washing the slides in PBS and wiping around the tissues, add two drops of warm anti-digoxigenin peroxidase conjugate to the sections and incubate for 30 minutes in a humidified container.After washing in PBS, prepare working strength-peroxidase substrate, cover the sections with peroxidase substrate, and stain for five minutes. Place the slide under the microscope and determine the optimal staining time. After washing the slides in a staining rack and distilled water, incubate the slides in distilled water for five minutes.Counter-stain using hematoxylin for two minutes. Wash the slides by placing them under running tap water for three minutes and then in distilled water. Mount the slides under glass cover slips and mounting medium and leave flat to dry.Observe under a light microscope. The percentage of affected cells was calculated using a light microscope. The results indicated that the treatment with oxalic acid significantly affected the cells in the midgut.Immunostaining showed positive red or brown reaction products in the apoptotic nuclei of hypopharyngeal glands. Positive reaction product after imidacloprid or coumaphos treatment was determined in the majority of glandular cells. When lifting of the mask of the bee head, take care not to damage or pull off the parts of the hypopharyngeal glands.This technique detects subclinical changes in bees and is also suitable for the detection of other environmental effects on bees and some other living organisms.

histology-basics-and-cell-death-detection-in-honeybee-tissue

Research

JoVE Journal

Biology

Actin Co-Sedimentation Assay; for the Analysis of Protein Binding to F-Actin

The actin cytoskeleton within the cell is a network of actin filaments that allows the movement of cells and cellular processes, and that generates tension and helps maintains cellular shape.  Although the actin cytoskeleton is a rigid structure, it is a dynamic structure that is constantly remodeling.  A number of proteins can bind to the actin cytoskeleton.  The binding of a particular protein to F-actin is often desired to support cell biological observations or to further understand dynamic processes due to remodeling of the actin cytoskeleton. The actin co-sedimentation assay is an in vitro assay routinely used to analyze the binding of specific proteins or protein domains with F-actin.  The basic principles of the assay involve an incubation of the protein of interest (full length or domain of) with F-actin, ultracentrifugation step to pellet F-actin and analysis of the protein co-sedimenting with F-actin.  Actin co-sedimentation assays can be designed accordingly to measure actin binding affinities and in competition assays.

Proteins bind to filamentous actin (F-actin) through distinct actin binding modules. In this video we demonstrate the procedure of actin co-sedimentation, which is an in vitro assay routinely used to analyze proteins or specific domains that bind F-actin.

The actin cytoskeleton within the cell is a network of actin filaments that allows the movement of cells and cellular processes, and that generates ...

Undecalcified Bone Preparation for Histology, Histomorphometry and Fluorochrome Analysis

Undecalcified bone histology demonstrates the micro-architecture of bone. It shows both the mineralised and cellular components of bone, which provides vital information on bone turnover or bone formation and resorption. This has tremendous importance in a variety of clinical and research applications. It yields beautiful images1 and allows for techniques such as fluorochrome assessment and histomorphometry2. Fluorochrome analysis is a technique where fluorescent dyes that bind to calcium are injected at a particular time point, which allows for quantification of the amount of mineralisation at that given time. Histomorphometry is a process of bone quantification at the microscopic level. 
Performing undecalcified bone histology is technically challenging, particularly with large size specimens. It requires variations in technique from those used in standard paraffin embedded histology. This video illustrates the process of producing good quality sections and demonstrates the technical difficulties and methods with which to overcome them. Specimen preparation, fixation and processing are achieved with a manner similar to other soft tissues, however due to the density and lower permeability of bone considerably longer fixation and processing times are required, often taking several weeks. Embedding is achieved using a supporting medium with similar or equal hardness and density to the bone such as methacrylate- based resins, but unlike paraffin infiltration and embedding, this is an irreversible step. Sectioning can be achieved by grinding which produces a thicker section, which is optimal for studies such as fluorochrome analysis. This is best achieved using a diamond blade on a macrotome. Alternatively, thinner sections can be produced for light microscopy and this is achieved using a sledge microtome with a very sharp blade. The sledge microtome provides the additional strength and stability required for large, hard blocks. Resin embedded sections can be stained with a variety of stains, which are demonstrated.

Undecalcified bone histology provides important information for a variety of clinical and research applications. It is technically challenging, particularly with large size specimens. This video illustrates the process of producing good quality sections and demonstrates the technical difficulties and methods with which to overcome them.

Undecalcified bone histology demonstrates the micro-architecture of bone. It shows both the mineralised and cellular components of bone, which provides ...

A &#946;-glucuronidase (GUS) Based Cell Death Assay

We have developed a novel transient plant expression system that simultaneously expresses the reporter gene, &beta;-glucuronidase (GUS), with putative positive or negative regulators of cell death. In this system, N. benthamiana leaves are co-infiltrated with a 35S driven expression cassette containing the gene to be analyzed, and the GUS vector pCAMBIA 2301 using Agrobacterium strain LBA4404 as a vehicle. Because live cells are required for GUS expression to occur, loss of GUS activity is expected when this marker gene is co-expressed with positive regulators of cell death. Equally, increased GUS activity is observed when anti-apoptotic genes are used compared to the vector control. As shown below, we have successfully used this system in our lab to analyze both pro- and anti-death players. These include the plant anti-apoptotic Bcl-2 Associated athanoGene (BAG) family, as well as, known mammalian inducers of cell death, such as BAX. Additionally, we have used this system to analyze the death function of specific truncations within proteins, which could provide clues on the possible post-translational modification/activation of these proteins. Here, we present a rapid and sensitive plant based method, as an initial step in investigating the death function of specific genes.

A &amp;#946;-glucuronidase GUS Based Cell Death Assay

Programmed cell death assays commonly used in mammalian systems such as DNA laddering or TUNEL assays, are often difficult to reproduce in plants. In combination with a GUS reporter system, we propose a rapid, plant based transient assay to analyze the potential death properties of specific genes.

We have developed a novel transient plant expression system that simultaneously expresses the reporter gene, &beta;-glucuronidase (GUS), with putative ...

Use of LysoTracker to Detect Programmed Cell Death in Embryos and Differentiating Embryonic Stem Cells

Programmed cell death (PCD) occurs in adults to maintain normal tissue homeostasis and during embryological development to shape tissues and organs1,2,6,7. During development, toxic chemicals or genetic alterations can cause an increase in PCD or change PCD patterns resulting in developmental abnormalities and birth defects3-5. To understand the etiology of these defects, the study of embryos can be complemented with in vitro assays that use differentiating embryonic stem (ES) cells.
Apoptosis is a well-studied form of PCD that involves both intrinsic and extrinsic signaling to activate the caspase enzyme cascade. Characteristic cell changes include membrane blebbing, nuclear shrinking, and DNA fragmentation. Other forms of PCD do not involve caspase activation and may be the end-result of prolonged autophagy. Regardless of the PCD pathway, dying cells need to be removed. In adults, the immune cells perform this function, while in embryos, where the immune system has not yet developed, removal occurs by an alternative mechanism. This mechanism involves neighboring cells (called "non-professional phagocytes") taking on a phagocytic role-they recognize the 'eat me' signal on the surface of the dying cell and engulf it8-10. After engulfment, the debris is brought to the lysosome for degradation. Thus regardless of PCD mechanism, an increase in lysosomal activity can be correlated with increased cell death.
To study PCD, a simple assay to visualize lysosomes in thick tissues and multilayer differentiating cultures can be useful. LysoTracker dye is a highly soluble small molecule that is retained in acidic subcellular compartments such as the lysosome11-13. The dye is taken up by diffusion and through the circulation. Since penetration is not a hindrance, visualization of PCD in thick tissues and multi-layer cultures is possible12,13. In contrast, TUNEL (Terminal deoxynucleotidyl transferase dUTP nick end labeling) analysis14, is limited to small samples, histological sections, and monolayer cultures because the procedure requires the entry/permeability of a terminal transferase.
In contrast to Aniline blue, which diffuses and is dissolved by solvents, LysoTracker Red DND-99 is fixable, bright, and stable. Staining can be visualized with standard fluorescent or confocal microscopy in whole-mount or section using aqueous or solvent-based mounting media12,13. Here we describe protocols using this dye to look at PCD in normal and sonic hedgehog null mouse embryos. In addition, we demonstrate analysis of PCD in differentiating ES cell cultures and present a simple quantification method. In summary, LysoTracker staining can be a great complement to other methods of detecting PCD.

We present a simple protocol to visualize regions of programmed cell death (PCD) in mouse embryos and differentiating embryonic stem (ES) cell cultures using a highly soluble dye called LysoTracker.

Programmed cell death (PCD) occurs in adults to maintain normal tissue homeostasis and during embryological development to shape tissues and ...

RNA In situ Hybridization in Whole Mount Embryos and Cell Histology Adapted for Marine Elasmobranchs

Marine elasmobranchs are valued animal models for biomedical and genomic studies as they are the most primitive vertebrates to have adaptive immunity and have unique mechanisms for osmoregulation 1-3. As the most primitive living jawed-vertebrates with paired appendages, elasmobranchs are an evolutionarily important model, especially for studies in evolution and development. Marine elasmobranchs have also been used to study aquatic toxicology and stress physiology in relationship to climate change 4. Thus, development and adaptation of methodologies is needed to facilitate and expand the use of these primitive vertebrates to multiple biological disciplines. Here I present the successful adaptation of RNA whole mount in situ hybridization and histological techniques to study gene expression and cell histology in elasmobranchs.
Monitoring gene expression is a hallmark tool of developmental biologists, and is widely used to investigate developmental processes 5. RNA whole mount in situ hybridization allows for the visualization and localization of specific gene transcripts in tissues of the developing embryo. The expression pattern of a gene's message can provide insight into what developmental processes and cell fate decisions a gene may control. By comparing the expression pattern of a gene at different developmental stages, insight can be gained into how the role of a gene changes during development.
While whole mount in situ's provides a means to localize gene expression to tissue, histological techniques allow for the identification of differentiated cell types and tissues. Histological stains have varied functions. General stains are used to highlight cell morphology, for example hematoxylin and eosin for general staining of nuclei and cytoplasm, respectively. Other stains can highlight specific cell types. For example, the alcian blue stain reported in this paper is a widely used cationic stain to identify mucosaccharides. Staining of the digestive tract with alcian blue can identify the distribution of goblet cells that produce mucosaccharides. Variations in mucosaccharide constituents on short peptides distinguish goblet cells by function within the digestive tract 6. By using RNA whole mount in situ's and histochemical methods concurrently, cell fate decisions can be linked to gene-specific expression.
Although RNA in situ's and histochemistry are widely used by researchers, their adaptation and use in marine elasmobranchs have met limited and varied success. Here I present protocols developed for elasmobranchs and used on a regular basis in my laboratory. Although further modification of the RNA in situ's hybridization method may be needed to adapt to different species, the protocols described here provide a strong starting point for researchers wanting to adapt the use of marine elasmobranchs to their scientific inquiries.

RNA In situ Hybridization in Whole Mount Embryos and Cell Histology Adapted for Marine Elasmobranchs

By combining methods for RNA whole mount in situ hybridization and histology, gene expression can be linked with cell fate decisions in the developing embryo. These methods have been adapted to marine elasmobranchs and facilitate the use of these animals as model organisms for biomedical, toxicology and comparative studies.

Marine  elasmobranchs are valued animal models for biomedical and genomic studies as  they are the most primitive vertebrates to have adaptive immunity ...

Dissection of the Auditory Bulla in Postnatal Mice: Isolation of the Middle Ear Bones and Histological Analysis

In most mammals, auditory ossicles in the middle ear, including the malleus, incus and stapes, are the smallest bones. In mice, a bony structure called the auditory bulla houses the ossicles, whereas the auditory capsule encloses the inner ear, namely the cochlea and semicircular canals. Murine ossicles are essential for hearing and thus of great interest to researchers in the field of otolaryngology, but their metabolism, development, and evolution are highly relevant to other fields. Altered bone metabolism can affect hearing function in adult mice, and various gene-deficient mice show changes in morphogenesis of auditory ossicles in utero. Although murine auditory ossicles are tiny, their manipulation is feasible if one understands their anatomical orientation and 3D structure. Here, we describe how to dissect the auditory bulla and capsule of postnatal mice and then isolate individual ossicles by removing part of the bulla. We also discuss how to embed the bulla and capsule in different orientations to generate paraffin or frozen sections suitable for preparation of longitudinal, horizontal, or frontal sections of the malleus. Finally, we enumerate anatomical differences between mouse and human auditory ossicles. These methods would be useful in analyzing pathological, developmental and evolutionary aspects of auditory ossicles and the middle ear in mice.

We present a protocol to isolate the auditory bulla, capsule, and ossicles from postnatal mice for whole mount and histological analysis.

In most mammals, auditory ossicles in the middle ear, including the malleus, incus and stapes, are the smallest bones. In mice, a bony structure called ...

Proteolytically Degraded Alginate Hydrogels and Hydrophobic Microbioreactors for Porcine Oocyte Encapsulation

In reproductive biology, the biotechnology revolution that began with artificial insemination and embryo transfer technology led to the development of assisted reproduction techniques such as oocyte in vitro maturation (IVM), in vitro fertilization (IVF) and cloning of domestic animals by nuclear transfer from somatic cell. IVM is the method particularly of significance. It is the platform technology for the supply of mature, good quality oocytes for applications such as reduction of the generation interval in commercially important or endangered species, research concerning in vitro human reproduction, and production of transgenic animals for cell therapies. The term oocyte quality includes its competence to complete maturation, be fertilized, thereby resulting in healthy offspring. This means that oocytes of good quality are paramount for successful fertilization including IVF procedures. This poses many difficulties to develop a reliable culture method that would support growth not only of human oocytes but also of other large mammalian species. The first step in IVM is the in vitro culture of oocytes. This work describes two protocols for the 3D culture of porcine oocytes. In the first, 3D model cumulus-oocyte complexes (COCs) are encapsulated in a fibrin-alginate bead interpenetrating network, in which a mixture of fibrin and alginate are gelled simultaneously. In the second one, COCs are suspended in a drop of medium and encapsulated with fluorinated ethylene propylene (FEP; a copolymer of hexafluoropropylene and tetrafluoroethylene) powder particles to form microbioreactors defined as Liquid Marbles (LM). Both 3D systems maintain the gaseous in vitro culture environment. They also maintain COCs 3D organization by preventing their flattening and consequent disruption of gap junctions, thereby preserving the functional relationship between the oocyte, and surrounding follicular cells.

Presented here are two protocols for the encapsulation of porcine oocytes in 3D culture conditions. In the first, cumulus-oocyte complexes (COCs) are encapsulated in fibrin-alginate beads. In the second, they are enclosed with fluorinated ethylene propylene powder particles (microbioreactors). Both systems ensure optimal conditions to maintain their 3D organization.

In reproductive biology, the biotechnology revolution that began with artificial insemination and embryo transfer technology led to the development of ...

Quantitative Proteomics Workflow using Multiple Reaction Monitoring Based Detection of Proteins from Human Brain Tissue

The proteomic analysis of the human brain tissue over the last decade has greatly enhanced our understanding of the brain. However, brain related disorders continue to be a major contributor of deaths around the world, necessitating the need for even greater understanding of their pathobiology. Traditional antibody-based techniques like western blotting or immunohistochemistry suffer from being low-throughput besides being labor-intensive and qualitative or semi-quantitative. Even conventional mass spectrometry-based shotgun approaches fail to provide conclusive evidence to support a certain hypothesis. Targeted proteomics approaches are largely hypothesis driven and differ from the conventional shotgun proteomics approaches that have been long in use. Multiple reaction monitoring is one such targeted approach that requires the use of a special mass spectrometer called the tandem quadrupole mass spectrometer or triple quadrupole mass spectrometer. In the current study, we have systematically highlighted the major steps involved in performing a successful tandem quadrupole mass spectrometry-based proteomics workflow using human brain tissue with an aim to introduce this workflow to a broader research community.

The protocol aims to introduce the use of a triple quadrupole mass spectrometer for Multiple Reaction Monitoring (MRM) of proteins from clinical samples. We have provided a systematic workflow starting from sample preparation to data analysis for clinical samples with all the necessary precautions to be taken.

The proteomic analysis of the human brain tissue over the last decade has greatly enhanced our understanding of the brain. However, brain related ...

Adipose Tissue-Derived Stem Cell Isolation and Characterization

Isolation and Identification of Mesenchymal Stem Cells Derived from Adipose Tissue of Sprague Dawley Rats

Adult mesenchymal cells have revolutionized molecular and cell biology in recent decades. They can differentiate into different specialized cell types, in addition to their great capacity for self-renewal, migration, and proliferation. Adipose tissue is one of the least invasive and most accessible sources of mesenchymal cells. It has also been reported to have higher yields compared to other sources, as well as superior immunomodulatory properties. Recently, different procedures for obtaining adult mesenchymal cells from different tissue sources and animal species have been published. After evaluating the criteria of some authors, we standardized a methodology that is applicable to different purposes and easily reproducible. A pool of stromal vascular fraction (SVF) from perirenal and epididymal adipose tissue allowed us to develop primary cultures with optimal morphology and functionality. The cells were observed adhered to the plastic surface for 24 h, and exhibited a fibroblast-like morphology, with prolongations and a tendency to form colonies. Flow cytometry (FC) and immunofluorescence (IF) techniques were used to assess the expression of the membrane markers CD105, CD9, CD63, CD31, and CD34. The ability of adipose-derived stem cells (ASCs) to differentiate into the adipogenic lineage was also assessed using a cocktail of factors (4 &#181;M insulin, 0.5 mM 3-methyl-iso-butyl-xanthine, and 1 &#181;M dexamethasone). After 48 h, a gradual loss of fibroblastoid morphology was observed, and at 12 days, the presence of lipid droplets positive to oil red staining was confirmed. In summary, a procedure is proposed to obtain optimal and functional ASC cultures for application in regenerative medicine.

Author Spotlight: Isolation and Identification of Mesenchymal Stem Cells Derived from Adipose Tissue of Sprague Dawley Rats  

This protocol describes a methodology for isolating and identifying adipose tissue-derived mesenchymal stem cells (MSCs) from Sprague Dawley rats.

Adult mesenchymal cells have revolutionized molecular and cell biology in recent decades. They can differentiate into different specialized cell types, in ...

Neutrophil Lifespan Extension with CLON-G and an In Vitro Spontaneous Death Assay

The average lifespan of a neutrophil is less than 24 h, which limits basic research on neutrophils and the application of neutrophil studies. Our previous research indicated that multiple pathways could mediate the spontaneous death of neutrophils. A cocktail was developed by simultaneously targeting these pathways, caspases-lysosomal membrane permeabilization-oxidant-necroptosis inhibition plus granulocyte colony-stimulating factor (CLON-G), which prolonged the neutrophil lifespan to greater than 5 days without significantly compromising the neutrophil function. Concurrently, a reliable and stable protocol for assessing and evaluating neutrophil death was also developed. In this work, we show that CLON-G can prolong the neutrophil lifespan in vitro to more than 5 days, and we exhibit the lengthening of the neutrophil lifespan with FACS and confocal fluorescence microscopy. This report introduces procedures for the preparation of CLON-G and showcases an in vitro spontaneous death assay of neutrophils, which can be used for the study of neutrophils and for subsequently interrogating neutrophil death, thus providing a reliable resource for the neutrophil community.

Neutrophil Lifespan Extension with CLON-G and an In Vitro Spontaneous Death Assay

This protocol details the preparation of CLON-G to extend the neutrophil lifespan to greater than 5 days and provides a reliable procedure for evaluating neutrophil death with flow cytometry and confocal fluorescence microscopy.

The average lifespan of a neutrophil is less than 24 h, which limits basic research on neutrophils and the application of neutrophil studies. Our previous ...